The present invention is directed generally to improvement in a wheel hub and in particular to an improved wheel hub structure for receiving an accessory mounted thereto. Another aspect of the invention is directed to novel cooperating structure provided on both a wheel hub and an accessory to facilitate the mounting of the accessory to the wheel hub.
Wheels for tricycles, bicycles or exercise cycles generally comprise a central hub and a plurality of spokes or other means coupling the hub to a rim for mounting a suitable tire or the like. Heretofore many such wheels have been constructed primarily of metallic materials, requiring that rim, hub and spokes be separately constructed and assembled. To save significantly on the cost of such wheels, various molded plastic one-piece wheels have been proposed. Generally speaking, in such structures hub, spokes and rim are molded in a single molding operation.
However, in the aforementioned applications (bicycles, etc.) various accessories must also be coupled to one or more of the wheels, and in particular to the wheel hubs. In this regard, bicycles or the like require some drive means such as a chain driven sprocket, or alternatively, a braking mechanism, such as a coaster brake, both of which are commonly mounted to the wheel hub. Additionally, great savings are realized if the interior hub diameter of all such molded one-piece wheel structures are fixed, and a separate bushing or the like is inserted to accommodate this diameter to a given axle.
From the foregoing, it will be seen that the coupling of the desired sprocket, brake or crank to a wheel hub requires some additional parts and assembly. In the case of a one-piece molded wheel structure, the economies realized in provision of the structure may rapidly be lost in the modifications, assembly steps and extra parts required to mount such accessories to the hub.